1. Field of the Invention
The embodiments of the invention generally relate to phase adjusting and mixing circuits and, more particularly, to a novel multiple source-single drain semiconductor device that can be incorporated into a phase adjusting circuit and/or a mixing circuit.
2. Description of the Related Art
With recent advances in semiconductor technology, integration levels have increased to the point where the functional capabilities of a single system-on-a-chip (SOC) produced today may exceed those of an entire computer that was produced less than five years ago. For example, complex analog functions (e.g., high speed serial interfaces) are routinely integrated into such SOCs. Operation of such high speed serial interfaces commonly requires a means of phase synchronization to correctly sample incoming data. Such phase synchronization can be accomplished using a phase rotator designed to mix several phase-related signals in order to create a selectable phase offset. However, while adequate for current clock speeds and de-serialization usage, phase rotators are typically large, expensive, complex and have limited frequency/granularity. Additionally, technological advancements have recently been made allowing for embedded radio frequency (RF) functions within larger digital integrated circuits. Typical RF functions commonly require demodulator circuits for effective sampling of high frequency transmissions with a lower speed functional clock. As with phase rotators, these demodulator circuits may be large and complex. Therefore, there is a need in the art for a circuit topology which provides for low cost input signal phase-adjustment capability in order to fine tune input signal arrival and data synchronization in digital systems.